Forwarding allows network packets on one interface (i.e. eth0) to be forwarded to another network interface (i.e. eth1). T
This allows Linux to connect ("ethernet bridge") or route network traffic.
The bridge configuration will merge two (or several) networks into one single network topology.
IpTables firewall rules can be used to filter traffic.
A router configuration can support multicast and basic IP routing using the "route" command.
IP masquerading (NAT) can be used to connect private LAN to the internet or load balance servers.
Turn on IP forwarding to allow Linux computer to act as a gateway or router.
/proc/sys/net/ipv4/ip_forward //file shows if the cpu is forwarding //if value =1 then, yes, you are.
Default is 0. One can add firewall rules by using ipchains.
Another method is to alter the Linux kernel config file: /etc/sysctl.conf
net.ipv4.ip_forward = 1